package com.book.backend.utils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

/**
 * 生成登录验证码
 *
 */
public class VeificationgCode {
    //图片宽度
    private int width = 100;
    //图片高度
    private int height = 30;
    private String[] fontNames = {"宋体","楷体","隶书","微软雅黑"};
    //设置图片背景为白色
    private Color bgColor = new Color(255,255,255);
    private Random random = new Random();
    private String codes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    // 记录随机字符串
    private String text;

    /**
     * 验证码随机获取一种背景颜色
     * @return
     */
  private Color randomColor(){
      int red = random.nextInt(150);
      int green = random.nextInt(150);
      int blue = random.nextInt(150);
      return new Color(red,green,blue);
  }

    /**
     * 随机获取验证码字体
     * @return
     */
    private Font randomFont(){
        String name = fontNames[random.nextInt(fontNames.length)];
        int style = random.nextInt(4);
        int size = random.nextInt(5)+24;
        return new Font(name,style,size);
    }

    /**
     * 获取一个随机字符
     *
     * @return
     */
    private char randomChar(){
        return codes.charAt(random.nextInt(codes.length()));
    }

    /**
     * 创建一个空白的BufferedImage对象
     *
     * @return
     */
    private BufferedImage createImage(){
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        g2.setColor(bgColor);
        g2.fillRect(0,0,width,height);
        return image;
    }
    public BufferedImage getImage(){
        BufferedImage image = createImage();
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            String s = randomChar() + "";
            sb.append(s);
            g2.setColor(randomColor());
            g2.setFont(randomFont());
            float x = i * width * 1.0f / 4;
            g2.drawString(s,x,height - 8);
        }
        this.text = sb.toString();
        drawLine(image);
        return image;
    }

    /**
     * 绘制干扰线
     * @param image
     */
    private void drawLine(BufferedImage image) {
        Graphics2D g2 = (Graphics2D) image.getGraphics();
        int num = 5;
        for (int i = 0; i < num; i++) {
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int x2 = random.nextInt(width);
            int y2 = random.nextInt(height);
            //设置干扰线颜色
            g2.setColor(randomColor());
            //指定干扰线的宽度
            g2.setStroke(new BasicStroke(1.5f));
            g2.drawLine(x1,y1,x2,y2);
        }
    }

    public String getText(){
        return text;
    }

    /**
     * 输出验证码图片
     * @param image   图片
     * @param out   格式
     * @throws IOException  io流
     */
    public static void output(BufferedImage image, OutputStream out) throws IOException {
        ImageIO.write(image,"JPEG",out);
    }
}

